New York (CNN) -- Exposure to debris at Ground Zero may be linked to heart problems in police officers, according to a new study announced Saturday.

The study revealed that police officers who worked at the World Trade Center site in the aftermath of the September 11, 2001, terror attacks had unusually high occurrences of abnormal left and right ventricular functioning, leading doctors to consider the role Ground Zero played in their diminished heart function.

The study, which started in January 2008 and ended in June, was funded by the Fraternal Order of Police of New York State. The study was not intended at first to focus on the effects of Ground Zero, but rather to test the strains of the job, said Dr. Lori Croft, the study's lead investigator.

Many Ground Zero workers have been reported to suffer from lung ailments after exposure to dust and debris at the site, but this is the first study that offers evidence that work at Ground Zero may lead to cardiovascular problems, said Croft of the Mount Sinai Medical Center.

Once microscopic matter is inhaled, it can result in harmful scarring to the lungs and heart, said Croft.

Croft said that a healthy person's heart muscle relaxes when it fills with blood. In the cases of the study participants, Croft said the heart remains somewhat stiff, which hinders blood flow and can lead to heart disease later in life.

Croft tested about 1,200 police officers over an 18-month period and found that 53 percent had abnormal left ventricular functioning and 59 percent had problems with their right ventricle. This would come as little surprise if they were in their 80s, but the mean age in the group was 49, Croft said.

"If you're talking about 80-year-olds with these statistics, that's one thing," she said. "But these are people in their 40s and 50s. That's unusual."

About 7 percent of 50-year-olds have this problem, Croft said.

Croft said some questions remain. Law enforcement is generally a stressful occupation and police often work varying shifts and might sit in a patrol car for long periods -- all unhealthy for the heart, she said.

The study, while revealing, needs to be further explored, she said. For example, testing police officers in other cities might help put the findings in context, she said.